diff --git a/.travis.yml b/.travis.yml
index cd4165ea..5d0a8753 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,7 +25,7 @@ before_install:
   - export OPAMVERBOSE=1
   - opam switch ${OCAML_VERSION}
   - eval `opam config env`
-  - opam install ocamlfind dune iter
+  - opam install ocamlfind dune iter camlzip
   - if ${RUN_TEST}; then opam install containers ; fi
 install:
   - make build
diff --git a/dune-project b/dune-project
index 977e7d75..7655de07 100644
--- a/dune-project
+++ b/dune-project
@@ -1,2 +1 @@
 (lang dune 1.1)
-(using menhir 1.0)
diff --git a/src/main/Dimacs_parse.mly b/src/main/Dimacs_parse.mly
index 3ad9341b..408b8db9 100644
--- a/src/main/Dimacs_parse.mly
+++ b/src/main/Dimacs_parse.mly
@@ -21,21 +21,14 @@
 
 prelude:
   | P CNF LIT LIT { () }
-  | error
-    {
-      failwith @@ Format.asprintf "expected prelude %a" pp_pos ($startpos,$endpos)
-    }
 
 clauses:
-  | l=clause* { l }
-  | error
-    {
-      failwith @@ Format.asprintf "expected list of clauses %a"
-        pp_pos ($startpos,$endpos)
-    }
+  | { [] }
+  | clause clauses { $1 :: $2 }
 
 file:
-  | prelude l=clauses EOF { l }
+  | prelude clauses EOF { $2 }
 
 clause:
-  | l=LIT+ ZERO { l }
+  | ZERO { [] }
+  | LIT clause { $1 :: $2 }
diff --git a/src/main/dune b/src/main/dune
index 96d0cc4a..073ec30f 100644
--- a/src/main/dune
+++ b/src/main/dune
@@ -10,5 +10,5 @@
                   -unbox-closures -unbox-closures-factor 20)
   )
 
-(menhir (modules Dimacs_parse))
+(ocamlyacc (modules Dimacs_parse))
 (ocamllex (modules Dimacs_lex))